Hot top structure



Dec. 10, 1968 w. M. CHARMAN, JR., ET AL 3,415,483

HOT TOP STRUCTURE Original Filed Sept. 23, 1964 IO 20 27 20 20a. 1 /l3 INVENTORS' WALTE R M. CHARMAN J? BY BENJAMIN E ANTHONY M, 55 ATTORNEW United States Patent 3,415,483 HOT TOP STRUCTURE Walter M. Charman, Jr., Shaker Heights, and Benjamin F. Anthony, Cleveland Heights, Ohio, assignors to Oglebay Norton Company, Cleveland, Ohio, a corporation of Delaware Continuation of application Ser. No. 398,629, Sept. 23, 1964. This application Apr. 12, 1967, Ser. No. 630,464 11 Claims. (Cl. 249-201) ABSTRACT OF THE DISCLOSURE A hot top structure which is supported at the upper end of an ingot mold includes a hollow metal casing having inwardly extending upper and lower ledge portions. An insulating lining is supported in the metal casing between the ledge portions. A protective refractory insert means comprising a plurality of refractory panels is located in the casing to provide a protective layer for the insulating lining. The insert means comprises a plurality of refractory panels mounted in a flexible backing which interconnects the panels for relative angular movement from a side-by-side position to a position for insertion into the casing. The insert panels extend beyond the flexible backing at both ends thereof. A bottom ring underlies a lower end portion of the casing and has a cooperating portion engageable with a projecting portion of the panels for supporting the panels in the casing, and the upper projecting portions of the panels engage the inwardly located end surface of the upper ledge portion of the casing.

H0! top structure This is a continuation of application, Ser. No. 398,629, filed Sept. 23, 1964, and now abandoned.

The present invention relates to hot top structures, and more particularly to an improved hot top having an annular refractory layer formed by a plurality of preformed refractory panels.

A hot top, as is well known, is used in conjunction with an ingot mold. The hot top is positioned above the mold and has an opening through which molten metal is poured into the mold, and which is filled with molten metal during the pouring operation. The hot top functions to maintain enough of the poured metal molten as long as it is necessary to feed the shrinkage of the solidifying ingot in the mold. Known hot tops include a metal casing with an insulating lining therein and a protective refractory layer overlying the insulating lining in order to protect the insulating from contact by the molten metal. The protective refractory layer has been constructed of a plurality of panel inserts which abut each other and together form a complete layer defining the opening through which the molten metal is poured into the ingot. The hot top structure of the present invention comprises panel insert means for insertion in a hot top casing to define the central opening therethrough. The insert means comprises a plurality of insert panels which have their back sides connected to flexible material which extends between the panels with the panels being movable relative to each other so that they can be moved into edge-abutting relationship to prevent leakage of steel therethrough. The backing material on the back side of the panels extends short of the top of the panel and downwardly to a position preferably short of the bottom of the panels but preferably so as to contact the bottom ledge of the hot top casing for supporting a brick lining which is to be protected by the panel insert means. The top portions of the panels extend upwardly to overlie a top ledge of the hot top casing above the bricks with the backing terice minating short of the top ledge of the hot top casing. The cardboard or other backing engages the refractory lining and preferably acts as a stop to limit the insertion of the insert means.

Objects and advantages of the present invention will be apparent to those skilled in the art to which it relates from the following detailed description of the preferred embodiment thereof made with reference to the accompanying drawings forming a part of this specification and in which:

FIG. 1 is a side elevational view, partly in section, of a hot top embodying the present invention;

FIG. 2 is an enlarged fragmentary sectional view of the hot top shown in FIG. 1 illustrating a portion thereof;

FIG. 3 is an enlarged fragmentary sectional view of another portion of the hot top shown in FIG. 1; and

FIG. 4 is an elevational view of the refractory layer in the hot top shown in FIG. 1 prior to assembly in the hot top.

The preferred embodiment of the present invention is illustrated in FIG. 1 and comprises a hot top 10 supported in the upper end of an ingot mold 11. The hot top 10 has a central opening 10a therethrough through which molten metal is poured into the ingot mold 11. During the pouring operation, the hot top 10 is filled with molten metal, and, as is well known, the hot top maintains enough of the metal in a molten state to feed the shrinkage of the solidifying ingot. The hot top 10 includes refractory insulating materials so as to maintain the metal in its molten state and, specifically, includes a hollow metal casing 13 which supports a refractory insulating lining 14 and a protective refractory layer 23 which overlies the insulating lining 14. The refractory layer 23 defines the opening 10a through the hot top 10 and contacts the molten metal and protects the insulating lining 14 from direct contact with the molten metal in the hot top.

The metal casing 13 of the hot top 10 includes an upper section 16 and a lower section 17 suitably secured together. The upper section 16 is provided at its upper end with an integral inwardly extending canopy or ledge 20 and which extends around the casing 13. The lower section 17 of the metal casing has at its lower end an integral inwardly extending canopy or ledge 21 which is preferably of less inward extent than the canopy 20 and which extends around the section 17.

The insulating lining 14 carried by or supported by the casing 13 is positioned between the inwardly extending surfaces 20a and 21a of the canopies 210 and 21, respectively. The insulating material of which the insulating lining 14 is constructed may take many forms and, by Way of example, may comprise a porous, fragile, insulating firebrick or a castable refractory of similar insulating properties. The insulating lining 14 is semipermanent in nature in that it may be used for a number of pouring operations due to the protection which is provided it by the refractory layer 23.

The lower end of the insulating lining 14, as viewed in FIG. 1, does not extend inwardly of the hot top beyond the ledge 21 of the metal casing 13 and may be said to be flush with the innermost end surface 21b of the ledge 21. The upper end of the insulating lining 14 is spaced a slight distance inwardly of the outermost end surface 20b of the canopy 20, and the lining 14 is provided with an inner surface 14a having a gradual taper due to differences in the extent of the lining at the opposite ends of the metal casing. The surface 14a tapers inwardly of the hot top 10 as the lining 14 extends upwardly. The advantages of this structure will be made clear as the description proceeds.

The material of which the insulating lining 14 is constructed has a maximum rated use temperature such that the lining 14 would be destroyed or so severely damaged by the thermal shock of direct contact with molten metal that it would have to be replaced for each pouring operation. This destruction or damaging of the lining 14 also would be increased because of the mechanical abuses to which it would be subject during the stripping of the hot top. from the sinkhead after the ingot has attained the desired degree of solidification. The insulating lining 14 of the hot top is protected, in the present embodiment, from the thermal shock and mechanical abuses by the refractory layer 23 which provides a sufficient temperature drop or gradient between the temperature of the molten metal and the temperature to which the insulating lining 14 is subject so that the latter temperature is well within the rated use of the lining 14, and as a result the lining 14 is a semipermanent lining capable of being reused for a number of pouring operations.

The refractory layer 23, in the present embodiment, forms an annular protective layer around the interior of the hot top and defines the opening 10a therethrough. The refractory layer 23, as shown in FIG. 4, comprises a plurality of individual panels 25 and 26 which form side and corner panels, respectively, and are secured to a flexible member 27 in any suitable manner, for example, by adhesive or mechanical means, such as rivets, pins, or clips. Alternatively, the panels may be molded and formed directly on the flexible material during the manufacture of the units.

The flexible member preferably is made of corrugated cardboard. However, it is to be understood that any flexible material which has suflicient strength to support the insert panels 25, 26 could be used. For example, cloth, cardboard strips, paper, fibrous material, or pressuresensitive tape may also be used. Moreover, a reinforcing wire screen may, be used as the flexible member and may be embedded in the panels 25, 26. The panels 25, 26 are supported by the flexible member and, in the preferred embodiment, are positioned on the cardboard sheet 27 in such a way that the adjacent annular edges 40 and 41, respectively, of the panels are parallel and a small spacing 45 is provided between each of the panels. The spacing 45 is such that the refractory layer 23 may be easily folded by grasping its opposite ends and folding the flexible material along a line in the space 45 between the panels to an angle necessary to bring the adjacent edges of the panels into engagement. The positioning of the panels 25, 26 is such that when the flexible material is folded, the edges of the panels properly mate and have a surface area contact therebetween and form a hollow geometric figure.

During the preparation of the hot top for the pouring operation, the refractory layer 23 is placed in the hot top. Specifically, the hollow geometric figure formed by the folded refractory layer is positioned over an inverted hot top and pushed into position. The cardboard material, of course, is a compressible material and as the insert unit is pushed into the hot top, the cardboard will engage the tapered inner surface 14a of the lining 14 and will compress somewhat and provides a suflicient pressure surface area contact between the panels 25 and 26, and specifically between the vertical edges 40, 41 thereof, thus providing a tight contact between the vertical edges of the. adjacent panels.

In the illustrated embodiments, the cardboard material 27 does not completely overlie the panels 25, 26. A small portion 30 of each panel extends beyond the cardboard at one edge 27a thereof, while a portion 31 of each panel extends beyond the cardboard at the other edge 27b thereof. The portions 30 of the panels extend so as to overlie the inner surface 20b of the canopy 20 and terminate flush with the upper end of the metal casing 13. The refractory layer by overlying the inner surface 20b of the canopy 20 greatly minimizes the flow of molten metal between the canopy and the refractory layer caused by overfilling the hot top, which metal would contact the insulating lining and cause damage thereto.

The portion 31 of the panels 25, 26 is received in a recess 36 in a bottom ring member 37 secured onto the bottom of the hot top in a conventional manner by suitable attaching clips, not shown. The bottom ring is located beneath the ledge 21 and is separated from the insulating lining 14 by the ledge 21. Positioning the portion 31 of the panels in the recess 36 minimizes leakage of the molten metal into the area behind the panels where it might contact and damage the lining 14. Moreover, by constructing the lining 14 so as to have its lower end flush with the inner surface 21b of the ledge 21, contact of the molten metal with the lining 14 is even further minimized since the ledge 21 has a surface area contact with the insert unit 23 at a location between the lining 14, on the one hand, and the abutting end of the portion 31 of the panels and the recess 36 of the bottom ring, on the other hand. This surface area contact of casing ledge 21b thus provides a metal chill ring to help solidify any metal which might leak behind the insert at the joint between insert portion 31 and ring recess 36, before such metal flows up and contacts lining 14.

Further, the extension of the casing ledge 21 to completely support insulating lining 14 and to contact insert unit 23 helps prevent erosion of the soft insulating lining 14 after repeated pouring at area 14b for several inches above casing ledge 21b. Such erosion of the insulating lining 14 in this area which occurs if the insulating lining at area 14b overlies and projects inwardly beyond the casing ledge 21 creates a large void back of the insert at this joint, which void may flood with molten steel when leaks occur at the ring and insert joint, causing a steel collar to be formed in back of the insert between the in sert and the lower part of the insulating lining, resulting in severe damage to both the insulating lining and casings. The present structure as shown has eliminated this void back of the insert and has virtually eliminated the formation of such damaging steel collars.

It should be apparent from the above description that the refractory layer 23 is supported or backed up so that outward movement of the insert panels 25, 26 due to the force of the molten metal applied to the layer 23 is negligible. The bottom ring 37 and the ledge 21 support the bottom of the insert so that it does not move outwardly of the hot top upon pouring of the molten metal, which outward movement would result in opening up of the area between the adjacent edges 40, 41 of the panel 25, 26 and cause leakage therebetween. The ledge 20 against which the upper end of the refractory layer 23 bears provides a similar support for the upper end of the panels. Furthermore, the surface 14a of the lining 14 functions to support the refractory layer 23 in a similar manner. Moreover, in the event the cardboard 27 is destroyed in the pouring operation, the panels 25, 26 are still supported from movement outwardly by the bottom ring 37 at one end and the canopy 20 at the other end.

The edge 27a of the candboard which is adjacent to portion 30 of the panels functions as a stop means for the insert unit, and particularly for the panels in the refractory layer so as to properly position it in the hot top. As noted hereinabove, the lining 14 is spaced from the outermost end surface 2% of the ledge 20 a slight distance. This distance is approximately the width or the thickness of the flexible cardboard 27. The edge 27a, as the refractory layer 23 is being inserted into the hot top, is guided by the tapered surface 14a of the lining 14 and rides along it and then engages the ledge 20 which projects inwardly beyond the surface 14a. Specifically, it contacts a surface portion 33 of the flange or canopy 20 of the metal casing which surface is tapered and provides a guiding surface for the end 27a of'the cardboard. Thus, the refractory layer is pushed into the hot top and stopped by the engagement of the cardboard with the tapered surface portion 33, whereby the panels are properly positioned and are substantially flush with the upper end of the hot top.

The bottom ring 37 of the hot top 10, of course, may be secured on the hot top casing 13 in any conventional manner and a wiper strip 38 is also included on the hot top 10. The details of the bottom ring and wiper strip are known in the art and will not be described. The Wiper strip and bottom ring, of course, function in the usual and conventional manner.

It should be noted that since the central opening a of the hot top is tapered, the refractory layer 23 when collapsed, that is, when in its flat condition, as illustrated in FIG. 4, is segmented and somewhat curved and when folded, forms a trapezoidal shape. Moreover, the panels 25, 26 are tapered. The particular shape of the panels of the refractory layer 23, of course, will vary depending upon the shape of the hot top in which they are to be used, and Whether or not the opening in the hot top is tapered.

It should be apparent that the preferred embodiment of the present invention has been described hereinabove in considerable detail and that certain modifications, adaptations and changes therein may be made by those skilled in the art to which it relates, anud it is to be understood that it is intended to hereby cover all such modifications, changes, and adaptations which come within the scope of the appended claims.

Having described our invention, we claim:

1. A hot top structure for use in association with a hollow hot top casing having spaced inwardly extending upper and lower ledge portions each having an end surface portion located inwardly of the outer periphery of the casing, said structure comprising a protective refractory insert means adapted to be inserted into the hollow casing, said protective refractory insert means comprising a plurality of insert panels having a height not substantially less than the height of said casing and engageable with the inner end surface portions of said ledge portions, said protective refractory insert means including stop means engageable with said upper ledge portion upon insertion into the hot top casing so as to properly position the insert means with the upper end thereof substantially flush with the outer surface of said upper ledge portion.

2. A hot top structure as defined in claim 1 wherein said insert means includes a flexible backing material to which said insert panels are connected and which is foldable at a location between said panels to move said panels relatively from a side-by-side position to a position defining a form which is insertable in the said casing to define said opening.

3. A hot top structure to be supported in the upper end of an ingot mold and having an opening therethrough through which molten metal is poured into the mold comprising a hollow metal casing having spaced upper and lower ledge portions projecting inwardly from the outer periphery of the casing with the upper ledge portion projecting inwardly a distance greater than the lower ledge portion and wherein said ledge portions have end surface portions located inwardly of the casing, an insulating lining supported by said casing between said ledge portions, said insulating lining having its lower end flush with said end surface portion of the lower ledge member and having a tapered inner surface which tapers inwardly of the hot top casing as it extends toward the upper ledge portion and which at its upper end is spaced slightly outwardly of the inner end surface of the upper ledge portion, a bottom ring member secured to said metal casing and underlying said lower ledge portion and having a portion extending inwardly of the metal casing beyond the inner end surface of said lower ledge portion which portion of said bottom ring has an annular recess or step therein, a protective refractory layer defining said opening in said hot top and comprising a plurality of panel members supported on a flexible backing material which is foldable to position the panel members so as to form a hollow figure insertable into the hot top casing to define said opening therethrough, said panel members extending at their opposite ends beyond the opposite ends of said flexible material on which they are mounted with the panels at one end extending beyond the flexible material a distance substantially equal to the length of said inned end surface of said upper ledge portion and extending beyond the flexible backing material at the other end a distance substantially equal to the depth of said recess or step in said bottom ring, said upper edge of said flexible backing material engaging the undersurface of said upper ledge member portion which projects inwardly beyond the upper end of said insulating lining thereby functioning as a stop so as to position the upper end of the panels substantially flush with the uppermost end of the upper ledge portion, said projecting end portions of said panels at one end thereof engaging the inner end surface portion of the upper ledge and at the other end thereof engaging a surface of the bottom ring defining said recess, and said flexible backing material engaging the inner end surface of the lower ledge portion.

4. A hot top structure to be supported at the upper end of an ingot mold and having an opening therethrough through which molten metal is poured into the mold comprising a hollow metal casing having spaced inwardly extending upper and lower ledge portions each having an end surface portion located inwardly of the outer periphery of the casing, an insulating lining supported by said metal casing between said ledge portions, a protective refractory insert means comprising a plurality of refractory panels for defining said opening at least in part and a sheet-like flexible hinge means forming a backing on which said panels are secured and connecting said panels for relative angular movement from a side-by-side position to a position defining said opening at least in part, said insert means having a first surface portion defining said opening in said hot top and a second surface portion opposite said first surface portion in engagement with said inwardly located surface portions of each of the ledge portions, said insert panels extending beyond said flexible backing at both ends thereof, and a bottom ring underlying the lower ledge portion of said casing and having a cooperating portion engageable with the projecting portion of said panel members for supporting the panel members in said casing and the upper end of said panels engaging the inwardly located end surface of the upper ledge portion.

5. A hot top structure for insertion into a hollow hot top casing having spaced inwardly extending upper and lower ledge portions each having an end surface portion located inwardly of the outer periphery of the casing and an insulating lining supported by the casing between the ledge portions; said hot top structure comprising a protective refractory insert means comprising a plurality of insert panel members for defining an opening and flexible backing material to which said members are connected and which is foldable at a location between said members to move said panel members relatively from a side-byside position to a position defining a form which is insertable into the hollow casing to define an opening therethrough, said insert means having a height not substantially less than the height of the casing, said insert means having a first surface for defining said opening and a second surface opposite said first surface and engageable with innermost end surface portions of the ledge portions of the hot top casing and overlying said insulating lining, one end of said panel members projecting beyond the backing material a distance substantially equal to the length of the inner end surface portion of one of the ledge portions so as to be engageable with said surface portion and be flush with the upper end surface thereof and the edge of said flexible backing material comprising a stop means engageable with the underside of said one ledge portion to prevent further movement of the insert means into said casing beyond the point where the projecting end portion of the insert means is substantially flush with the upper surface of said one ledge portion.

6. A hot top structure for insertion into a hollow hot top casing having spaced inwardly extending upper and lower ledge portions each having an end surface portion located inwardly of the outer periphery of the casing and an insulating lining supported by the casing between the ledge portions; said hot top structure comprising protective refractory insert means comprising a plurality of insert panel members for defining an opening and flexible backing material to which said members are connected and which is foldahle at locations between said members to move said panel members relatively from a sideby-side position to a position defining a form which is insertable into the hollow casing to define an opening therethrough, said insert means having a height not substantially less than the height of the casing, said insert means having a first side for defining said opening and a second side opposite said first side and engageable with the innermost end surface portions of the ledge portions of a casing and overlying the insulating lining; said second side opposite said first side being defined by back surface of the insert panel members and the back surface of said flexible backing material which is opposite the surface on which the panel members are secured, the back surface of the flexible backing material being engageable with the inner end surface of the lower ledge portion of the casing and the back surface of the panel members being engageable with the inner end surface of the upper ledge portion of the casing.

7. A hot top structure for use in a hot top of the type supported at the upper end of an ingot mold and having an opening therethrough through which molten metal is poured into the mold and formed of a hollow metal casing having spaced inwardly extending upper and lower ledge portions each having an end surface portion located inwardly of the outer periphery of the casing a bottom ring underlying the lower ledge portion of the casing, and an insulating lining supported by said metal casing between said ledge portions; said hot top structure comprising protective refractory insert means comprising a plurality of refractory panels and a sheet-like flexible hinge means forming a backing on which said panels are secured and connecting said panels for relative angular movement from a side-by-side position to a position defining a portion of said opening, said insert means having a first surface portion defining said opening in said hot top and a second surface portion opposite said first surface portion for engaging inwardly located surface portions of each of the ledge portions of said hot top, said panels extending beyond said flexible backing at both ends thereof and providing at one end thereof a projecting portion engageable with a cooperating portion of said bottom ring for supporting the panels in the hot top casing, the upper end of said panels being engageable with an inwardly located end surface of the upper ledge portion.

8. A hot top structure for use in a hollow hot top casing having spaced upper and lower ledges at the top and bottom of the casing respectively which extend inwardly of the outer periphery of the casing and each of which terminates in an end surface extending generally axially of the casing and which has a bottom ring in juxtaposition to the bottom of the casing which bottom ring has a horizontally exposed support surface below the top of the bottom ring which extends inwardly of the lower ledge in a direction away from the outer periphery of the casing, the hot top structure comprising a plurality of insert panels having front sides for defining a central opening through the casing and back sides opposite thereto,

and flexible backing material to wiich said panels are connected at their back sides and which is foldable at locations between said panels to move said panels from side-byside positions to relative positions defining a form which is disposable in the casing to define said opening, said panels having a height greater than the distance etween the support surface of the bottom ring and the bottom of the upper ledge and said backing material generally covering the backs of said panels but terminating short of the bottoms of said panels a distance which is substantially the distance of the support surface of the bottom ring below the top of the bottom ring and extending toward the tops of said panels a distance substantially equal to the distance between the bottom of the upper ledge and the top of the bottom ring whereby the top portions of the panels are exposed for engagement with the end surface of the upper ledge and the top of the backing material functions as stop means for positioning the structure in the casing.

9. A not top structure for use in association with a hollow hot top casing having spaced inwardly extending upper and lower ledges each having an inner end face extending generally axially of the casing, said structure comprising panel insert means for insertion into said casing to define a central opening, said insert means comprising a plurality of insert panels having front sides for defining said opening and a height substantially the same as the hot top casing and flexible backing material to which said panels are connected on their back sides with said backing material terminating short of the tops of said panels to provide stop means engageable with the upper ledge upon insertion into the hot top casing so as to properly position the insert means in said casing with the top ends of said panels extending over and engaging the inner face of the upper ledge of the casing.

it). A hot top structure for use in a hollow hot top casing having spaced upper and lower ledges at the top and bottom of the casing respectively which extend inwardly of the outer periphery of the casing and each of which terminates in an end face extending generally axially of the casing, said structure comprising a bottom ring in juxtaposition to the bottom of the casing which bottom ring has a recess defining an exposed horizontal support surface below the top of the bottom ring extending inwardly of the lower ledge from a vertical wall of the recess which is positioned to be displaced inwardly of generally axial alignment with the innermost part of the inner end face of the lower ledge by a predetermined distance and insert means adapted to extend over and engage the lower ledge of the casing and comprising a plurality of insert panels having front sides for defining a central opening through the casing and back sides opposite thereto, and flexible backing material to which said panels are connected at their back sides and which is foldable at locations between said panels to move said panels from side-by-side positions to relative positions defining a form which is disposable in the casing to define said opening, said backing material having a thickness substantially the same as said predetermined distance, said panels having a height greater than the distance between said support surface of the bottom ring and the bottom of the upper ledge to extend over the inner end face of the upper ledge and said backing material generally covering the backs of said panels but terminating short of the bottoms of said panels a distance which is substantially the distance of the support surface of the bottom ring below the top of the bottom ring to expose the bottoms of the panels for reception in the bottom ring.

11. A panel insert unit for use in association with a hollow hot top casing having spaced inwardly extending upper and lower ledges each having an inner end face extending generally axially of the casing and said upper ledge having a downwardly facing surface extending transverse to the axis of the casing, said unit having a front side and a rear side remote therefrom and comprising a plurality of heat destructible refractory panel sections having front faces for forming adjacent interior faces of a hot top opening, said panel sections having a side edge surface facing each adjacent panel section with the side edge surfaces each being in a plane defining an obtuse included angle with the front face of the panel section, material extending between and interconnecting said panel sections adjacent the rear side of the unit and providing for relative angular movement of said panel sections from an openedout shipping position where facing edge surfaces of adjacent panel sections are spaced to a position where the spaced edge surfaces of adjacent panels are in substantial cont-act to position the panels to form interior faces of the hot top and to block leakage of molten metal between the panels, said insert unit having a first portion engageable with said downwardly facing surface of said upper ledge upon insertion into the casing and a second portion of refractory material extensible over the end face of the upper ledge when the second portion engages said downwardly facing surface.

References Cited UNITED STATES PATENTS J. SPENCER OVERHOLSER, Primary Examiner. E. MAR, Assistant Examiner.

US. Cl. X.R. 249-113 

